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PFAS in drinking water: Montana

EPA UCMR 5 results for 45 public water systems. 5 had at least one PFAS detected; 2 had a highest single PFOA or PFOS result above 4.0 ppt.

UCMR 5 is a one-time EPA monitoring program, not a compliance determination. The values shown are the highest single sample result at any of the system's sampling points; one result above 4.0 ppt does not mean the system violates the PFAS rule, which is judged on running annual averages under separate compliance monitoring. Results describe the public water system, not an individual home.

Water systemServesPFOA max (ppt)PFOS max (ppt)PFAS detected
Alpine Village Wua
MT0003229		WhitefishND4.11
Anaconda Water Department
MT0000016		AnacondaNDND0
Belgrade City Of
MT0000136		BelgradeNDND0
Big Pines Trailer Court
MT0000450		MissoulaNDND0
Big Sky County Water and Sewer Dist 363
MT0002385		Big SkyNDND1
Bigfork County Water and Sewer
MT0000262		BigforkNDND0
Billings City Of
MT0000153		BillingsNDND0
Black Rock Estates Subdivision
MT0004881		BillingsNDND0
Bozeman City Of
MT0000161		BozemanNDND0
Butte Silverbow Water Dept
MT0000170		ButteNDND0
Co Water Dist of Billings Heights
MT0000155		BillingsNDND0
Columbia Falls City Of
MT0000181		Columbia FallsNDND0
Culligan Water Conditioning Great Falls
MT0002630		Great FallsNDND0
Dillon City Of
MT0000201		DillonNDND0
Fairfield Town Of
MT0000212		FairfieldNDND0
Flathead County Water and Sewer
MT0001744		KalispellNDND0
Frenchtown High School
MT0000856		FrenchtownNDND0
Glendive City Of
MT0000229		GlendiveNDND0
Great Falls City Of
MT0000525		Great FallsNDND0
Hamilton City Of
MT0000234		HamiltonNDND1
Hardin City Of
MT0000235		HardinNDND0
Havre City Of
MT0000524		HavreNDND0
Helena Water System
MT0000241		HelenaNDND0
Kalispell Public Works
MT0000259		KalispellND6.62
Laurel Municipal Water System
MT0000270		LaurelNDND0
Lewistown City Of
MT0000271		LewistownNDND0
Libby City Of
MT0000274		LibbyNDND0
Livingston City Of
MT0000573		LivingstonNDND0
Lockwood Water and Sewer District
MT0000156		BillingsNDND0
Malmstrom Air Force Base
MT0000515		Great FallsNDND1
Miles City City Of
MT0000291		Miles CityNDND0
Missoula Water
MT0000294		MissoulaNDND0
Montana State University Billings
MT0004788		BillingsNDND0
Montana State University Bozeman
MT0004790		BozemanNDND0
Phantom Hills Water System
MT0004379		MissoulaNDND0
Pinesdale Town Of
MT0002926		PinesdaleNDND0
Polson City Of
MT0000308		PolsonNDND0
River Rock County Water and Sewer Dist
MT0004082		BelgradeNDND0
Rocky Mountain College
MT0004796		BillingsNDND0
Shelby City Of
MT0000328		ShelbyNDND0
Sidney City Of
MT0000330		SidneyNDND0
Sun Prairie Village County
MT0000521		Great FallsNDND0
University of Montana
MT0004204		MissoulaNDND0
West Yellowstone Town Of
MT0003136		West YellowstoneNDND0
Whitefish City Of
MT0000357		WhitefishNDND0

ND = not detected (below the 4 ppt UCMR 5 reporting level). Values are the highest single sample result, not an annual average.

Source: EPA UCMR 5 final occurrence data (EPA page last updated 2026-08-28; samples collected January 2023 – December 2025) ↗.

PFAS disclaimer: PFAS results are copied from EPA's UCMR 5 dataset and describe samples taken at a public water system's entry points between 2023 and 2025, not water at any specific address. Levels may have changed since sampling (for example, after new treatment). “Not detected” means below EPA's UCMR 5 minimum reporting level, not zero. This is not a compliance determination or a water test. Contact your water utility for current information.